Rotatably driven godets, which are used in such applications as stretching and texturizing operations, are well-known in the textile industry. In such operations the godet serves the purpose to convey and heat the overrunning filaments, threads, etc., to a predetermined temperature.
For example, inductively heated godets are described in German Patent DT-PS No. 1,025,095 as well as in U.S. Pat. No. 3,187,150. In addition, a variation of a godet which may be inductively heated is shown in U.S. Pat. No. 3,562,487. This latter application describing a heated godet having a double wall forming a hermetically closed annular hollow space in which a liquid is contained.
Similarly, U.S. Pat. No. 3,487,187 describes another inductively heated godet whose magnetic flux is conducted through both its cylindrical outer shell and a rotational body of laminated metal plates, the laminated plates being formed in a radially-directed, U-shaped configuration. In this device, the shanks of the U-shaped plates form with the inner wall of the surrounding godet shell a narrow cylindrical, annularly-shaped gap which is concentrical to the axis of rotation of the godet. Such U-shaped formation of the stationary magnetic core of the godet is also known from the above-mentioned U.S. Pat. No. 3,187,150 and Swiss Pat. No. 477,578.
However, such U-shaped configurations have been found to be disadvantageous in use with respect to the assembly, maintenance and repair of the godet primary magnetic winding. Namely, since the coil must be wound about the fixed rotational body, which is fastened to the carrying body of the godet in the maintenance or repair of the coil the entire godet system must be disassembled and returned to the manufacturer for rewinding of the coil. An additional disadvantage with such systems, particularly with long body godets in high-speed applications, is that the resulting heating extends over only the central portion of the cylindrical godet shell. This leads to uneven heating of the shell in operation since in such applications there exists strong air turbulence over the face side of the godet which causes severe heat loss therein and in the adjoining edge zone of the godet shell over which the filaments run. Consequently, undesirable uneven heating and irregular processing of the filaments will occur in the operation of such systems.